In recent years, the use of marker systems has been particularly useful in preventing crime and for tracking and identifying the authenticity of items. Such marker systems, as have been developed by the applicant for many years, have found particular application in the fields of security, counterfeiting and crime prevention/deterrence, for example as described in WO 93/07233, GB 2369078, GB 2410208 and GB 2413675, amongst others. Analysis of the surface onto which the marker system is placed or deployed can provide a reliable method of tracing or authenticating items, articles, goods, vehicles or persons.
Bar codes have been used for a significant time and are an accepted way of marking items for identification. They provide data to uniquely identify the item to which they are attached; the data being optically represented. The most common types of barcodes in use are linear barcodes, such as the UPC and EAN barcodes, although two dimensional bar codes are also in use. The two dimensional barcode is based on providing indications at various points within a matrix, the positioning of the indications detailing the unique code.
Barcodes are now extensively used for tasks ranging from tracking mail, monitoring the stock levels, determining areas where employees have been, identifying patient information and provide details for grocery goods, etc. However, the use of barcodes has at least one major drawback. Barcodes are easy to copy, duplicate and/or modify. In fact, a readable copy of a barcode can be produced by simply taking a copy of the original using a standard photocopy machine. Because barcodes are so easy to copy, they are particularly vulnerable to fraudulent reproduction.
One way to reduce the risk of a barcode being copied, has been to provide a laminate layer which only allows infra red light to pass through over the barcode. The laminate layer prevents the barcode from being copied using a standard photocopier.
Additionally, some systems using a laminate layer will have the additional security feature of destroying the barcode underneath when someone attempts to remove the laminate layer.
However, even with this additional security measure, as infra-red scanners are commonplace, it has become relatively easy to duplicate the barcode contained underneath the laminate layer and therefore, barcodes remain vulnerable to culprit attack.
Other coding systems using materials that fluoresce under different forms of radiation have been developed as shown in WO2008113962A1 and US2007205284A1. However, these involve the use of fluorescent materials in pre-set positions. There is difficulty in printing a large number of images, each one of which is unique. Forms of printing such as thermal printing used for producing bar codes do not lend themselves easily for use with some fluorescent materials. Further, upconverting materials is difficult due to the weak emission of fluorescent materials and high concentration/coat weight required to obtain a measureable output.
Therefore, there is a need for an improved method and system for randomly generating a unique marker and additionally an improved method and system for identifying an object having a marker wherein the marker may have been randomly generated.